Abstract：Objective：To observe the effect of the therapy of Fuzheng Yiai Prescription combined with Gefitinib Tablets on immune function of patients with non-small cell lung cancer (NSCLC). Methods：A total of 80 patients with NSCLC were divided into the control group and the observation group by the random envelope method according to the admission number，with 40 cases in each group. The control group was given Gefitinib Tablets for treatment，and the observation group was treated with Fuzheng Yiai Prescription combined with Gefitinib Tablets. The clinical effects and indexes of immune function were compared before and after treatment between the two groups. Results： The total effective rate was 82.50% in the observation group，higher than that of 57.50% in the control group (P＜0.05). Before treatment，there was no significant difference being found in the comparisons of levels of CD3 + ， CD4 + ， CD4 +/CD8 + ， immunoglobulin A (IgA)，immunoglobulin G (IgG) and immunoglobulin M (IgM) between the two groups (P＞ 0.05)；after treatment，the levels of CD3+，CD4+，CD4+/CD8+，IgA，IgG and IgM in both groups were increased，and the CD8+ levels were decreased (P＜0.05)；the levels of CD3+，CD4+，CD4+/CD8+，IgA， IgG and IgM in the observation group were higher than those in the control group (P＜0.05)，and the CD8+ level was lower than that in the control group (P＜0.05). Conclusion： The therapy of Fuzheng Yiai Prescription combined with Gefitinib Tablets has a significant curative effect on NSCLC，which can improve the immune function and help increase the resistance to chemotherapy.